This invention relates in general to hypodermic syringes for manual injection and which have needles which auto-retract into a tubular component of the syringe known as an outer barrel after injecting a liquid dosage from an inner barrel and relates in particular to a hypodermic syringe with latch components for limiting or overriding latching movements of components prior to injection, during injection and needle retraction strokes corresponding to inward and outward movements of the syringe plunger.